can you write a DIP for it (even if it's for experimental only for now)?
It takes a bit more work, but it gathers all the info in 1 place and incorporate feedback. Right now there are too many scattered threads about that issue.

As I've suggested before, here's what I would want:

* dmd -check_arithmetic_overflow: not implied by any other flags (including -debug), because conflating flags is bad and it might slow down debug builds too much. So this opt-in flag results in no downspeed, unless user explicitly asks for it (usually when chasing a bug).

* code can query whether the flag is set via version(check_arithmetic_overflow){...}else{...}

* we need a way to unset the flag in a given scope because pieces of code may rely on intentional overflow, regardless of whether check_arithmetic_overflow was provided. This part is a bit tricky, any ideas? I've proposed this: http://forum.dlang.org/thread/mailman.835.1370430655.13711.digitalmars-d@puremagic.com#post-mailman.835.1370430655.13711.digitalmars-d:40puremagic.com (scoped compiler options (cf C++ pragma push/pop). Maybe there are other ways?




On Tue, Jun 4, 2013 at 11:54 PM, eles <eles@eles.com> wrote:
Dear all,

 The question of if the integers should overflow or not by default comes back now and then and latest was in this thread: http://forum.dlang.org/thread/mailman.739.1370297482.13711.digitalmars-d-learn@puremagic.com (and, before you ask, yes, by me).

 Yes, I am a supporter of this.

 But I am not sure if it is a good idea or no, although for me should be just like the -noboundscheck compiler flag, ie the runtime overhead will be included only on explicit request.

 But, while I do not dare asking for the feature to be in the language, could it be added to the compiler, for a while? Even as undocumented feature, for testing by those who would like to.

 Maybe some branch "experimental" or "throw-away" could be created to this end.

 After one month of using it people will have their arguments pro or contra supported not only by faith, but also by facts.

 Then, after one month, if is a bad feature and an undocumented one, silently remove it and, voilà, everything will be just as today is.

 Thank you.